I tested the first unit with it sitting on my desk, it stopped working after a short time, dead - nothing. I tried several other power cables, no joy.When the second unit arrived, I carefully handled and tested the unit on my desk.I tested my existing Micro USB cables with a phone and a tablet, flexing and moving the cable near the input, there was no connection loss.I used the included USB Micro USB cable as well as mine. with the GPS Speedometer.I quickly saw the loss of power when moving the See full review